Hi
I had a similar thing happen with my bf bub at about the same age, i took him ot the gp where she listened to his bowels etc and said he was all ok, just normal for a bf bub. If you are concerned maybe take bub to get checked. All i can say is watch out when he finally goes cause it will be a dosie.

My boy still has times where he goes for a week or so and other times when its a few times a day.